Peter Savage gives a short talk on Nagios, the network monitoring software. He covers configuration of hosts and services, and how to use the web interface. Some very basic knowledge of networking is required.
See http://www.hantslug.org.uk/cgi-bin/wiki.pl?TechTalks for more details and copies of the presentation that accompanied the talk. This talk was given at the Hampshire Linux User Group (HantsLUG) meeting on 1st October 2005 at Southampton University.